Aeroplane gun



Sem. 23, 1924.

E. ASPERRY AEROPLANE GUN 2 Sheets-.Sheet 1 Filed Jan. 1.2 1918 Sept. 23 1924.

AEROPLAN 1918 2 Sheets-Sheet .2

Filed Jan. l2

Patent Sept. 23, 12924.

EL A. SPERBY, O BROOKLYN, NEW YORK.

OPLN E GUN.

Applicationled January 12, 1918. Serial o. 211,472.

To all whom t may concern:

Be it known that I, ELMER A. SPERRY, a citizen of the United States of America, residing at 1505 Albermarle Road, Brooklyn, in the county of Kings and State of New York. have invented certain new and useful `Improvements in Aeroplane Guns, of which the following is a specification.

rIhisinvention relates to guns adapted to betired from aircraft, more specifically to a system of sovmouuting guns on aircraft as to render it possible to hit a target anywhere in space without turning the aircraft.

The principal object if the present invention is to provide a pair of guns on an aircraft so mounted as to render it possible to hit a target anywhere in space in any position of the aircraft on which said guns are mounted.-

Another object is to provide a gun capable of being supported below the aircraft and adapted to be oriented, sighted and fired from the aircraft. l

A. further object is to provide a novel system of sights for an aeroplane gun. Further objects and advantages will appear as the invention is hereinafter developed.

Referring to the drawings vwhich illustrate what I now consider the preferred form of my invention.

y Fig. 1 is a side elevation of an aeroplane with my invention applied thereto, certain parts being broken' away as indicated by dotted lines. y

Fig. 2 is a\detail elevation of one of the guns and'its support, the latter being shown in section. l

Fig. 3 is a detail elevation of the otherl l gun and its support, the latter being shown in section.

Fig. 4 is a section on the line 4 4 of Fig. 3.

Fig. 5 is a detail view of a preferred form of chassis for use in connection with my invention.

Fig. 6 is an enlarged detail of a portion of the structure shown in-Fig. 5.

Fig. 7 is a detail section illustratingone form of reel employed for elevating the chassis.

. Fig. 8 is a seion taken on the line 8-8 of Fig. 3. y E l Figs. 9 and 10 are diagrammatic views employed in explaining theoperation of the reectors employed in connection with at least one of my Fig. 11 is a vperspective of the aircraft shown in Fig. 1 with the guns shown in a different position.

Fig. 12 Jis a detail elevation illustrating a slight modification in the support for the upper gun.

It is important, if not essential, that4 aircraft employed in battle be equipped with guns capable of hitting a target anywhere in space without turning the aircraft on which the guns are mounted. I aim to accomplish the above recited result by employing only two guns on each aircraft and while -my invention is applicable to various forms of aircraft I have selected an aeroplane for the purposeslof illustration.

Referring to Figs. 1 and 11 it will be seen that I have illustrated an aeroplane 1 of the tractor type comprising a fuselage 2, having cockpits 3 and 4, and main planes 5 and 6. 'Iwo guns 7 and 8 are provided on said aeroplane and are so positioned that each is capable of sending its projectile at all targets in spaceinaccessible to thevother. `While the guns may be placed in various positions to satisfy this condition, I prefer to mount one of the guns above the other `as illustrated and I also prefer to provide means whereby the guns may be placed in a. position where they offer little resistance to the wind when theyy are not being used. 'Ihe upper gun 7 is shown as pivotally connected at 9. for oscillation about a normally horizontal axis, to a casing 10. The casing 10 is in turn mounted for rotation about the rounded portion 11 of an upright 12 which telescopes Within a socket member 13 secured to a platform 14 within the cockpit 3. The gun 7 may be raised and lowered by any suitable means such as a rack 15 provided on upright 12 and a lco-actiing pinion 16 carried by the socket 13. The

By firing zone I mean the locus of all positions of the muzzle axis of the gun in which a projectile will clear (i.e., not strike) any part of the aircraft. A. satisfactory firing zone for such a gun is one including a. complete sphere, except a cone having its apex substantially at 9, the angle between the axis 12 of said cone and any element being equal to, or less than, seventy degrees.

' The gun 7 .may be sighted and operated in the usual manner by a gunner or operator on the platform 14 and when not in use it maybe lowered to a position adjacent the mam plane 5 (see Fig. 11) in which it offers comparatively little impedance to the forward movement of the aircraft. It will be noted that the gun 7 and its support may be readily employed in the system disclosed in my companion case, Serial No. 208,390, tiled Dec. 22, 1917, the pivoted sight 106 and rotatable casing corresponding to the parts 6 and 3 in said companion case.

As pointed out above, the zone of fire of the gun 7 is limited, i. e., it is not a complete sphere.A rlhe gun 8, however, may be mounted in such a manner as to supplement the zone of lire of said gun 7, so that the combined zone of fire of the two guns will be a complete sphere. Thus the gun 8 may be placed below the aircraft when in operative position and in 'order to avoid dropping the .gun too far below its supporting craft it 'may be preferable to provide means for swinging the chassis up and out of the path o'f movement of the gun. One form of structure for accomplishing this function is shown in Figs. 1, 5, 6 and 7 and may be constructed substantially as follows:

The forward struts of the chassis, only one of which, 20, is shown in the drawings, are each formed of two sections hinged at 22, a sliding sleeve 23 beingL provided for the purpose of imparting rigidity to the hinge or knee 22 when launching or landing y of the 'aircraft is being effected. A spring 25 may .be provided on each of struts20, said springs 25l eachv abutting at one end a l pin 26- and at the other end a iange 24, provided on a correspondin sleeve. Itwill` be seen that the springs ten ,to hold the sleeves 23 over the knee-joints 22 in engagement `with pins 27,'so that normally 'the forward xstruts are rigid, (See Fi 6.) In order to raise the chassis Il provi e a wire or cable 29 connected at one end to an eye 30 provided lon leachof sleevesv 23, the other end o f said cable extending to the gunners cockpit 3 and preferably also to the pilots cockpit 4. The cable 29 is shown as passing' over a pulley 31 adjacentL the cockpit `3 an secured at 32 adjacent the cockpit 4. An additional cable 38 may secured at one end to the axle 33, passed-over a pulley 34,

secured to the fuselage 2, and wound'around a drum or reel 35 at its\ other end. .The drum 35 may be rotatably mounted in the cockpit 3 and may be provided with ratchet teeth 36 tadapted to be enga ed by a pawl A37 pivoted to the fuselage 2 or the purpose .of holding the cable 38 wound up on reel' 35. .When the chassis is in normal position, as indicated in dotted lines in Fig. 1, it may be elevated by pulling on cable 29 which will rst raise the sleeve 23 (see Fig. 5) and then bend the knee-joint 22, so that if the cable 38 is then drawn up on the reel 35 the chassis will assume its elevated position (see dotted line position in Fig. 5) out of the path of movement of the gun 8. I

The gun 8, as previously mentioned, is below the aeroplane when in operative or firing position. I prefer to provide means v for operating and sighting the gun from above, i. e., from the cockpit or other convenient position, and also means whereby the gun and its support may be elevated to a position when it will oi'er little resistance erative position it will be, seen that said gun I is shown pivotally connected to al support 42 by means of straps 40 secured to the gun Aand loosely mounted on pivot pins 41, 41 carried by said support. In order'to rotate.

or oscillate the gun 8 onrpivots 41 one of the straps may be secured to a worm wheel rotatably mounted on one of said pivot pins andmeshing with a worm 44. Preferably the support 42 is made in the formof a sleeve so that the shaft 45 of the worm 44 may be extended upwardly therethrou h. The last mentioned shaft may be rotataly mounted in ljournal brackets 46 secured to the support 42 and may be provided with a hand wheel or otheroperatin means 47.

The sleeve 42 is mounte about its longitudinal yaxis in collars 49, the -sleeve being prevented from moving longitudinally with respect to said collars 49 by means ofcollars 50i secured to the sleeve on both sides of the collars 49. A hand wheel or other suitable operating means 51 may be secured to the upper -part of sleeve 42 for for rotation l the purpose of rotating the latter. Obvi` ously by manipulating'the hand wheels 47 .and `51 thev gun`8 may be directed toward various points in space and the parts are so designed that the zone of fire of the gum l 8 will atleast include the points in space `inaccessible from the gl'111'7.-

Before describing, in deta1l, the. specific structure of the sighting mechanism the theor7 of operation thereof may best be understood by referring to Figs. 9 and 10.

While various types of reflectors or refract ing devices may be employed I have illustrated a pair of 45 degree glass prisms 52, 53.

Ifthe prism .53 has its movement restricted to rotation about a single axis, such as z', h, or an axis parallel thereto, and the prism 52 secured to the first named prism 53 but is capable of rotation with respect thereto about an am's g 7L, perpendicular to llne z' L and lying in a plane perpendicular to the degree face of prism 53, the adjacent faces 54, beingl constantly parallel; it will be seen that any incident ray or rays entering the prism 52 through and normal to the face 56 will be reflected in a direction coincident with or parallel to the axis i h.

ln Figs.A 3, 4 and 8, I have shown the prisms 53 and 52 carried by the support 42, the former directly connected to said support 42 with its axis i z, parallel to the axis of rotation of said support and the latter being carried by the gun 3 with theaxis g k coincident with the pivoted axis 41-41 of said gun 8. 'llhe line f g`may obviously be made the line of sight of the gun 8 (see Figs. 4 and 8) anda system of lenses 61 to 64 may be provided for focusing any reected image, of an object in the line of vsight f, g, upon cross-hairs 66 and for rendering such image visible at the eye-piece 65..

if desirable the elements 62 tol 66 may be carried by a tube 70 telescoping within a tube 71 in which the lens 61 may be mounted. @bviously the gun 8 may be sighted by merely -bringing the image of the target on the cross-hairs.

The tiring of the gun may be controlled from the cockpit by any suitable means such as a Bowden wire having one of its ends and the adjacent end of its sheath 73 secured to the trigger 75 and trigger guard 74 respeci tively. The Wire 72 may extend through the sleeve 42 and may be secured at its upper end to a lever 77 for operation thereby, and

. the upper end of the sheath 73 may be secured in a bracket 76 on sleeve 42. rlhe lever 77 may be pivoted to one of the spokes of the Wheel 51 and may be provided with a push button 7 9 which extends through the rim of said wheel whereby, by means of the same hand used in operating the wheel, the button may be depressed to cause a pull on the trigger 75 regardless of the angular position of the gun 8.

As previously point@ out, means are provided. for supporting the gun 8 either in its lower or operative position or in a position v such that the flight of the aeroplane will f not be interfered with. Thus the collars 49 may each be provided with integralpivot pins 81 and 82 (see Figs. 3`and 8) adapted to engage in slots 84 and 83 provided in plates which may be secured to the base of the aircraft. The slots 83 are each provided at one end with a straight portion 86 land at the other end with a straight portion 85. The slots 84 are each provided at opposite ends with depressed portions 87 and 88. @bviously when the sleeve 42 is in the position indicated in F' 3, the pins 81 and 82 are in the bottom o slots 88 and 86 respectively, so that the support 42 will be prevented from moving laterally. In order to elevate the gun and its support to inoperative position, it is only necessary'to raise the support 42 as by means of the hand wheel 51. a1idmove said support to the left as viewed in Fig. 3. The pivots 81 and 82 will then ride in the slots 84 and 83 respectively until thesepivots enter the slot portions 87 and when the gun will be held in raised position, as indicated in Fig. 1.

The operation of my invention may be briefly summarized as follows: After the aircraft on which the guns are at some target in space, using the `gun 8, the

chassisL may be elevated and the gun 8` lowered to operative position. The manipulation of the gun 8 and thesighting thereof may be accomplished from within the cockpit 3,'the operator standing on a platform 90 which may be provided for this purpose. If the target is beyond the zone of fire of the gun 8, the gun 7 may be elevated into operative position, and employed, the operator now standing on the platform 14. It is to be understood, of course, that if desirable, the gun 7 may be providedy with operating and sighting means similar to that provide for the gun 8.

Instead of pivotally connecting the upper n 7 to the casing 10 as indicated at 9 in ig. 2, the former may be xedly secured to said casing as indicated in Fig. 12. In this event the casing 10 may be pivotally secured to the member 12 for rotation about a horizontal axis 9 in addition to rotation aboutK the normally vertical axis 11. Pivots 9 and 11 will be seen to form, in eect, a universal pivot between upright 12 and casing 10.

ln accordance with the provisions ofthe if patent statutes. I have herein describedthe rinciple of operation of my invention, together with the apparatus, which I now con sider to represent the best embodiment thereof, but l desire to have it understood that the apparatus shown bis only illustrative and lUO that the invention can be carried out by y vthe combined zone of fire of said guns is a sphere, means for raising said first gun to effective position and lowering it to iueees` rtive 'fpositiom and means for lowering 'said f second gun to effective position and raising it to ineffective position. f' f k2.' In combination, an aircraft, a gun carried'therebyr at a point' cbelow the aircraft,

means for raising said 'gun to ra'point withf in the aircraft, and ymeansy controlled from they aircraft rfor lfiring the gunl when ybelow the aircraft. f 1 3. In'combination, an aircraft, a gun` carried thereby at a'point :below the aircraft,

means for raisingsaid gun to 'a point within the aircraft,y and means for sighting they un from the aircraft when said is in;

its lowermost position'.v

' f4. In combination, an aircraft, ya gun' ithereon, means for supportlng said gun for i universal movementy below sa1d alrcraft,

and'means fori sighting said gun fromy said aircraft. f f y 5.r AIn combination, an aircraft, a gun there' on;y means for supporting said gun for pivotal f movement below said aircraft, and rmeans y f yfor sighting said gun from isaid aircraft. f

6. vIn combination, an aircraft, afgun piv-y otally carriedthereby at apoint below saidr aircraft, and sighting means extending from f said gun to a point withinlsaid aircraft.

'v "7'. In combination, an aircraft, a gun, means for pivotally supportingisaid at a ypoint below said iaircraft and meansy extending 'from said gun to said r aircraft for orienting said .gun in both yazimuth and ele-v vation.k f

8. In comblnatlon, an aircraft, a gun, a

' supporting tube pivotally carrying sald gun and movably mounted with respectlto said aircraft, and means for supporting said tube either vwithin or without the aircraft.

9. In combination with the elements specified in claim 8, meanscarried by said tube for. orientingsaid gun.

10. In combination with the elements specified in claim 8, means carried by said tube for frin the gun.

.11. In com ination, a support, a .gun mounted for'oscillation about a given axis with respect thereto, a reector carried by f f '13.* Iny combination,

said'support, andareiector mounted on said 1 gun coaxially with saidr axis and arranged to reiiect rays constantly in a given direction 'with'respect to said support regardlessy of oscillations of the ygun about said axis.

i 12. ,combinatiom'r a .,support,` aV gunk mounted for oscillation withrespect thereto, ya reflector carriedby `said support and a rey iiector ymovable With said gun, the last men,- ytioned reiiectory being arranged to receive and toreflect said rays along the axis of os,- cillation of the gun.l

crays parallelito the line :of sight of the gunA y asupport,y ar'" gunv mounted'for oscillation withy respect theref to, ay reflecting member movable with said gun fand arranged toy receive; rays parallel to the line of sight of said gun yand to@ reiiect saidy rays along the axis of oscillationy of said gun, and a second reflecting member carried f byk saidsupport and arranged to reflect ysaid rays in a :constant directioniwith respectto said support.y f

-14.:Incombination, a tubular support, a 'l mounted for ,oscillationy with respect t thereto, a reiecting member rmovable lwith said 'guny and arranged to rreceive-raysl parallelitothe'line'ofssightoffsaid y and,y

to reflect. said rays along the axis o yo'scilla- 'f f rtionfoff,gsaid gun, anda: secondfreectin j membercarr'ied byr said tubular ,supporty an f arranged tokreiiect ysaid rays constantlyy rpar-y -allfeltoetheaxi's of said su port, f c

an a1rcraft, a

In testimony whereof I have aixed myV signature.

' ELMIER A. SPERRY.

1pivotally 

